Gear finishing machine with work transfer mechanism



Aug. 24, 1965 BR 3,202,057

GEAR FINISHING MACHINE WITH WORK TRANSFER MECHANISM Filed Oct. 51. 1960 2 Sheets-Sheet 1 B. F. BREGI Aug. 24, 1965 GEAR FINISHING MACHINE WITH WORK TRANSFER MECHANISM Filed OCT. 31. 1960 2 Sheets-Sheet 2 INVENTOR.

3,262,057 GEAR FINISHING MACHINE WITH WORK TRANSFER MECHANISM Benjamin F. Bregi, Grosse Pointe Shores, Mich., assignor to National Broach 85 Machine Company, Detroit,

Mich, a corporation of Delaware Filed Oct. 31, 196i Ser. No. 66,179 2 Claims. (Cl. 90-'1.6)

column having a forwardly extending rigid pedestal at its lower end, a first slide mounted for horizontal reciprocationon said pedestal, a second slide mounted for vertical movement on said column in position overlying said first slide, a rotary support carried by one of said slides, an adjustable support membercarried by the other of said slides, a second rotary support carried by said support member, power means for effecting horizontal reciprocation of said first slide on said pedestal, and drive means connected to one of said rotary supports.

It is a further object of the present invention to provide a machine as defined in the preceding paragraph comprising a member mounted on said pedestal for adjustment about a vertical axis and having ways thereon receiving one of said slides.

It is a further object of the present invention to provide a gear finishing machine including a column, a slide mounted for vertical movement on said column, vertical feed mechanism connected between said column and said slide, and clamping means acting between said column and slide and released only during operation of said feed means. i

Other objects and features of the invention will be come apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings, illustrating preferred embodiments of the invention,

arrangement.

Referring now to the drawings the machine comprises a frame indicated generally at It) including a column 12 and a forwardly extending rigid pedestal 14. The upper surface of the pedestal 14 constitutes a bed supporting a work support slide 16 connected to the pedestal by' United States Patent "vanced to pick up the work gear.

to permit rocking of the table 36 in timed relation to traverse. The rocking movement of the table 36, as is now well understood in the art, may be controlled to impart a crowned contour to the teeth of the work gear. The rocking movement of the table 36 is controlled by a cam 39 having a cam slot 40 therein which receives a follower pin 42.. The cam and cam follower are connected between the pedestal l4 and the rocking table 36, as best illustrated in FIGURE 2.

Rotary work support means is provided on the upper surface of the table 36 and this means comprises head and tailstocks 44 and 46 having centers 48 adapted to engage the ends of a work support shaft or fixture. The means for mounting the work gear is arranged to provide for substantially free rotation of the work gear carried thereby, the gear and its support means being rotated through meshed engagement with a gear-like tool as will subsequently be described.

Special means are provided for facilitating loading of the machine, particularly when the work gear is a relatively heavy structure. For this purpose there is provided a shaft 50 journaled in supports indicated at 52.

and 54 provided on the table 36. At one end the shaft includes a crank arm 56 pivotally connected to the piston rod of a piston 59 contained in a power cylinder 58. As shown, the cylinder 58 is carried by the bracket which includes the bearing 52. Splined or otherwise connected to the shaft 50 are a pair of arms 60 each including cradle blocks 62 shaped to accommodate a portion of the work gear or work gear supporting fixture.

As best seen in FIGURE 1, the arms 64 may be swung forwardly so that the work gear G may be lowered into the cradle blocks 62 without danger of accidentally engaging the gear finishing tool T. It will be readily ap parent from the figure that the machine is so designed that a massive work gear may if desired be brought into position by overhead conveyor means and lowered into rest on the cradle blocks provided on the support arms 60. Thereafter, fluid under pressure is admitted to the cylinder 58 and the arms are swung to the full line position, at which time the axis of the work gear G is brought into substantial alignment with the centers of the head and tailstocks, one of which may then be ad- Conveniently, the advance of a center to pick up the work gear may elevate the gear sufiiciently to provide clearance with respect to the cradle block.

Preferably, the work support includes a guard or housing structure indicated generally at 64.

Adjacent its upper end, the column 12 is provided with a relatively short forwardly extending portion 70 and below this portion there are provided vertical ways 72. The

. tool support slide 74 is provided with means slidably enrectilinear ways indicated at 18. Means are provided for effecting horizontal reciprocation of the slide 16 in the directionof the ways and this means comprises a motor 20 adapted to drive a feed screw 22 through suitable gearing including change gears indicated generally at 24. Associated with the feed screw 22 is a nut 26 carried at the underside of the slide 16. Back and forth reciprocation of the slide 16 is controlled by switches 28 p and 3.0 actuated by adjustable dogs 32 and 34 respectively. i p

While the work support may be mounted directly on the slide 16, it is preferred to provide a rocking table 36 which is connected to the slide 16 by a pivot shaft 38 gaging the vertical ways 72 so that the tool slide 74 is ver tically movable at the front side of the column 12 toward and away from the work slide 1 6 and the pivoted or crowning table 36 carried by the slide. Means are provided for effecting vertical movementof the tool slide 74 and this means comprises a feed screw 76 engaging a feed nut 78 fixed to the tool slide 74. The feed screw 76 is connected at its upper end with a drive gear 80 driven through an intermediate gear 82 by a gear 84 connected to a vertical shaft 86. The shaft 86 may be driven at a rapid traverse rate or a slow feeding rate in accordance with power feed mechanism which will now be described. p i

Referring to FIGURE 1 the feed motor is illustrated at 90 and is connect-ed to a drive worm 9-2 in mesh with worm gears 94 land 96, Worm gear 94 connects to a shaft 93 carrying a: worm in mesh with a worm gear W2. Worm gear 96 is connected to a shaft 1M carrying a bevel gear 1% in mesh with a bevel gear 1&8. Worm gear 162 and lbevel gear 1% are freely rota-table on shaft 86 and are adapted to be coupled thereto by a solenoid actuated clutch element 111? splined to the shaft 8:; and movable between one of its two limiting positions, in either of which it connects one of the gears 192, .188 to the shaft 86.

Adjacent its lower end the shaft 86 carries a worm 112 meshing Wltlll a worm gear .116 connected to a timing disc 1 18 carrying a plurality of adjustable switch actuating dogs 120 and 122. Adjacent the disc 113 are switches 124, 125 and 126.

Carried thy the tool slide 74 are a plurality of vertically adjustable switch actuating dogs 127, 128 and 129, and carried by the column 12 in position to be engaged by appropriate ones of the dogs are switches indicated at 131, 132 and 133. The operation of the feed mechanism including the several dogs and switches referred to will subsequently :be described.

Referring now to FIGURE 4 there is illustrated a somewhat diflerent embodiment of the invention than that previously described. In this case instead of providing a single vertical feed screw 76 there are provided a pair of such feed screws which in this instance are designated 76a, each of which has associated therewith a separate feed nut 78a. In this case the feed screws 76 carry gears 8% at their upper ends which are connected by an intermediate gear 8'1a. It will be appreciated that the gear 81a may be driven by a gear such as the gear 82 seen in FIGURE 1. The advantage of this arrangement is that the screw shafts 73a which in effect suspend the tool slide '74, may be separated a substantial distance to give more stability to the tool slide.

Connected to the underside of the forwardly extending portion 70 of the column 12 is a rigid bracket 13d carrying a sheave 136 over which is extended a cable or the like 138, the lower end of which is connected at 149 to the tool slide '74. Within the column 12 is provided a similar sheave 142 over which the cable is extended and a counterweight 144 is provided at the lower end of the cable. With this arrangement substantially the entire weight of the tool slide 74 and associated mechanism may be counterbalanced so as to provide smooth and easy movement thereof.

Means are provided for clamping the vertically movable tool slide 74 to the ways 72 on the column 12 whenever the vertical feed mechanism is not in operation. This means is diagrammatically illustrated at 146 and constitutes a spring lbiased clamp operable to engage the ways 7 2 with sufficient force to support the tool slide 74 against vertical movement despite any stresses developed during a gear finishing operation. The clamp 146 is preferably solenoid actuated and is of the type which is released when the solenoid is energized. The solenoid windings obviously may be connected to be energized whenever the feed motor 90 is energized and connected to the shaft d6 through the clutch 1 1i). Whenever the feed motor is deenergized the clamp automatically operates to support the slide against movement. It will of course be understood that the feed mechanism itself, including as it does worms and worm gears, may also serve as means for preventing movement of the tool slide whenever the motor 9@ is de-energized.

Suspended from the underside of the tool slide 74 is a tool head or support member 150. The support member d is mounted for angular adjustment about a vertical axis and includes a rotary support or spindle 155-2 for carrying a gear-like tool T.

, The present machine is designed to carry out crossed axes gear finishing such for example as gear shaving, gear lapping, orgear honing in which operation it is usual for the axes of the gear and tool to be crossed in space at an angle of between 3 and degrees. In FIGURE 1 the axis of the tool T is illustrated as at 90' degrees to the axis of the gear G, but this illustrated position was se lected merely for the purpose of best illustrating driving connections to the tool. In operation, the tool head would normally be swung to a posit-ion such that the axis of the tool would extend at a small angle with respect to the axis of the work gear G.

Means for effecting driving rotation of the tool T in different positions of angular adjustment and in different vertical positions is provided. For this purpose there is provided a forwardly extending bracket 154 on the column 12 in which is journaled a worm gear 156. This worm gear is driven by a worm 157 connected to a shaft 153, the opposite end of the shaft being connected through change gears 160 to a sprocket or pulley 162 connected by a flexible driving member 164 to the drive element 166 of the shafit of a tool drive motor 168.

The worm gear 156 has a splined drive connection to a vertical drive shaft 170 the lower end of which carries a bevel gear 172. Carried by the angularly adjustable tool head 150 is a shaft 174 carrying a bevel gear 176 meshed with the bevel gear 172. The shaft 174 carries a gear 173 which drives a gear connected to the tool spindle 152. Gears 178 and 180 may be indirect mesh or may include an idler gear 182 if desired.

From the foregoing it will be apparent that the motor 168 is effective to drive the tool T in rotation in all positions of angular adjustment of the tool and in all positions of vertical movement.

The operation of the mechanism, while apparent from the foregoing, will now be briefly described.

The reversible vertical feed motor 99 is a brake motor of the type in which a brake is applied instantaneously upon de-energization of the motor. The motor accordingly, when de-energized comes to an abrupt stop. As previously described, the motor drives the two worm gears 94 and 96. Assume that the tool slide 74 is in its uppermost position and that the work gear G has been engaged between centers and is in position directly below the tool T. At this time the clutch 11%] is engaged with the bevel gear train 166, 1%. Upon energization of the motor in the proper direction the tool slide '74 moves downwardly in rapid traverse until switch 132 is tripped. At this time the clutch engages with the worm gear 102 and the slide continues to move downwardly at a slow speed. Switches 124, 125 and 126 are de-energized during this part of the cycle until switch 133 is tripped. After switch 133 is tripped downward movement continues until switch 124 is tripped by its dog, and at this time the feed motor 90 stops. The work slide 16 is moved in traverse by the motor 211 and the finishing of the work gear commences. At the end of reciprocation of the work slide 16 in one direction one of the switches 23 or 30 is actuated by its dog which reverses the direction of traverse and also preferably reverses the direction of rotation of the tool drive motor 168. At the same time the feed motor 90 is again energized and the tool slide is fed downwardly until the next dog trips switch 125. This operation may be repeated as many times as desired, or as many times as there are dogs on the disc to trip the switch 125.

To conclude the cycle a special dog, such as 122., trips the switch 126 at which time the clutch is engaged with the bevel gear train, and the feed motor 90 is reversed and switches 124, 125 and 126 are tie-energized, and upward movement of the tool slide at a rapid traverse rate commences. Upward movement of the tool slide continues until switch 131 is actuated, thus completing the cycle.

The gear finishing operation performed by this machine may be a gear shaving operation in which the tool T is a hardened steel gear having its teeth gashed.

to provide a multiplicity of cutting edges. Alternatively, the tool may be in the form of a hone which is a gear raving teeth at least the surface portions of which are formed of a hard slightly yieldable, highly resilient resin compound such for example as epoxy resin, and including a multiplicity of separated abrasive grains embedded therein, some of which are exposed at the surface thereof. Alternatively, the tool may take other forms such for example as a lapping tool in the form of a cast iron lap. In any case, the gear finishing operation involves bringlng the teeth of the gear and tool into mesh under substantial pressure so that material will be removed from the teeth of the gear by the operation of the tool. Either the gear or tool, and in the present machine the tool, is driven in rotation at speeds appropriate to the finishing operation. The particular speed will vary with the particular operation, but in any case will be at least sufficient to produce a pitch line velocity of several hundred feet per minute. Inasmuch as the gear and tool are positioned at crossed axes, the instantaneous contact between the teeth is of limited extent. The relative traverse, which in this case is provided by traversing the slide 16 horizontally, for the purpore of distributing the finishing action uniformly from end to end of the gear teeth. This traverse is accordingly relatively slow, on the order of a few inches a minute. Where a crowning operation is to be performed, the rocking table 36 is rocked so that the finishing action is not uniform from end to end but instead removes additional material from adjacent the ends of the teeth of the gear.

The other relative movement which occurs during a single finishing cycle is the periodic feeding movement which in this instance is accomplished by downward movement of the slide 74. As previously described, this movement takes place at the end of a stroke and is provided in small increments as for example one or a few thousandths of an inch.

The incremental feed referred to is particularly appropriate for a gear shaving operation in which a single traverse stroke removes a predetermined amount of material from the gear teeth in a true cutting operation. Where the gear finishing operation is honing it may be carried out without positive incremental feed. For example, it may be carried out with the gear and tool under substantially constant radial pressure. Alternatively, the gear and tool may be moved into predetermined pressure contact and then locked against further radial approach or separation. Finally, pressure may be applied in an operation in which approach under predetermined pressure is permitted, but separation is either prevented or strongly opposed.

While the foregoing general description of the several operations in mind, it will be observed that the present machine is characterized by its extreme rigidity during a cutting or finishing traverse. This traverse is accomplished by movement of the slide 16 on the ways 18 which in turn are provided on the stationary and rigid pedestal portion 14 of the frame. Thus, the slide is given the most positive and rigid support possible during the traverse stroke. At the same time, during the traverse stroke the tool supporting slide 74 is rigidly locked to the ways 72 in such a way that it becomes in effect a unitary part of the frame structure.

During a particular gear finishing cycle, the tool head 150, which is angularly adjustable about a vertical axis on the slide 74, is rigidly locked in adjusted position to the slide by suitable means such as bolts or the like (not shown). Thus, in effect the tool T during any particular finishing stroke is rigidly supported in a stationary position which tends to produce the utmost potential accuracy in the finished gear.

By providing the work support slide 16 on the fixed and stationary pedestal portion 14 of the frame, the work support is provided at a constant height which may be selected to be the most convenient for the operator. This is to be contrasted with the prior machines in which the relative feed between the gear and tool is accomplished by vertical movement of the work support so that the work support is positioned at diiferent heights not only in loading and finishing a particular gear, but more particularly, when positioned to accommodate gears of different diameter. The present construction not only is most convenient for the operator, who thus is enabled to have the work support always at the most convenient height, but also lends itself particularly to automation in which a series of such machines may be positioned to receive work gears movable generally horizontally from machine to machine, or automated lines in which the Work gears may be advanced to the gear finishing machine from a gear roughing machine and may be moved from the gear finishing machine to gear gauging apparatus or the like.

During any particular gear finishing operation the frame structure including the vertically movable tool slide 74, which at this time is firmly locked to the column 12, constitutes a C-frame which is designed to have the highest rigidity and hence, to produce the greatest accuracy in the finished gears.

In FIGURE 3 there is shown an arrangement in which the rocking table such as 36 is omitted and a work support plate 35a is provided which is angularly adjustable about a vertical axis. In the figure angular adjustment is illustrated as provided by virtue of an adjusting: worm in connection with worm gear teeth mounted on the swiveled work support 36a.

The drawings and the foregoings specification constitute the description of the improved gear finishing machine in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

1. A gear finishing machine comprising a frame having a pedestal, horizontal ways on said pedestal, a work slide movable on said ways, a traverse motor in said pedestal, drive means connecting said traverse motor to said work slide, a rocking table on said work slide, rotary work support means on said table, a column at one side of said pedestal, vertical ways on said column, a tool slide movable on said vertical ways, a tool head carried at the underside of said tool slide in position to overlie said table, means providing for adjustment of said tool head relative to said tool slide about a vertical axis, rotary tool support means on said tool head, a drive motor in said column, drive means connecting said motor and tool support means, a tool feed motor in said column, feed screw means interconnecting said tool slide and column for moving said tool slide vertically between a loading position in which a tool carried by said tool support means is located above the position occupied by a work gear on said work support means in clearance therewith, and a working position in which a gear-like tool on said tool support means is in mesh with a work gear on said work support means, and a work gear transfer device mounted on said rocking table for movement therewith comprising a pair of arms having upper and lower ends, means pivoting the lower end of said arms to said table for swinging movement about an axis parallel to the axis of rotation of said work support means in any position of said table, work support means at the upper ends of said arms, the upper ends of said arms being movable in an are between a work receiving position spaced laterally from said tool slide to provide for movement of a heavy work gear vertically downward onto the work support means on said arms without interference from said tool slide and tool head and a working position in which a work gear carried thereby is directly beneath the position occupied by a tool on said tool support for engagement by said rotary work support means.

2. A machine as defined in claim 1 in which the work support means on said arms is located to position a work gear slightly below the position which it occupies when carried by said rotary work support means.

(References on following page) '2 5% References Cited by the Examiner 2,692,535 10/54 Praeg 90-1.6 2,733,641 2/56 Prage 90-1 UNITED STTES PATENTS 2,887,014 5/59 Praeg 901.6

6/13 Munsmg 192-20 X 10/33 Smith et a1. 822.7 5 O G PATENTS 12/40 Ridgway 90-16 9/41 ovfirstedt 329,388 5/30 Great Butaln. i fi ANDREW R. JUHASZ, Primary Examiner. Pe p rey 9 10/50 Pragg I WILLIAM W. DYER, JR., LEON PEAR, Examlnels. 

1. A GEAR FINISHING MACHINE COMPRISING A FRAME HAVING A PEDESTAL, HORIZONTAL WAYS ON SAID PEDESTAL, A WORK SLIDE MOVABLE ON SAID WAYS, A TRAVERSE MOTOR IN SAID PEDESTAL, DRIVE MEANS CONNECTING SAID TRAVERSE MOTOR TO SAID WORK SLIDE, A ROCKING TABLE ON SAID WORK SLIDE, A ROTARY WORK SUPPORT MEANS ON SAID TABLE, A CLOUMN AT ONE SIDE OF SAID PEDESTAL, VERTICAL WAYS ON SAID COLUMN, A TOOL SLIDE MOVABLE ON SAID VERTICAL WAYS, A TOOL HEAD CARRIED AT THE UNDERSIDE OF SAID TOOL SLIDE IN POSITION TO OVERLIE SAID TABLE, MEANS PROVIDING FOR ADJUSTMENT OF SAID TOOL HEAD RELATIVE TO SAID TOOL SLIDE ABOUT A VERTICAL AXIS, ROTARY TOOL SUPPORT MEANSA ON SAID TOOL HEAD, A DRIVE MOTOR IN SAID COLUMN, DRIVE MEANS CONNECTING SAID MOTOR AND TOOL SUPPORT MEANS, A TOOL FEED MOTOR IN SAID COLUMN, FEED SCREW MEANS INTERCONNECTING SAID TOOL SLIDE AND COLUMN FOR MOVING SAID TOOL SLIDE VERTICALLY BETWEEN A LOADING POSITION IN WHICH A TOOL CARRIED BY SAID TOOL SUPPORT MEANS IS LOCATED ABOVE THE POSITION OCCUPIED BY A WORK GEAR ON SAID WORK SUPPORT MEANS IN CLEARANCE THEREWITH, AND A WORKING POSITION IN WHICH A GEAR-LIKE TOOL ON SAID TOOL SUPPORT MEANS IS IN MESH WITH A WORK GEAR ON SAID WORK SUPPORT MEANSM AND A WORK GEAR TRANSFER DEVICE MOUNTED ON SAID ROCKING TABLE FOR MOVEMENT THEREWITH COMPRISING A PAIR OF ARMS HAVING UPPER AND LOWER ENDS, MEANS PIVOTING THE LOWER END OF SAID ARMS TO SAID TABLE FOR SWINGING MOVEMENT ABOUT AN AXIS PARALLEL TO THE AXIS 